1. Field of the Invention
This invention relates generally to keyboards, and more particularly, to a portable keyboard, having mostly normal or standard desktop keyboard size keys in a reduced size enclosure with a removable cover, for use with a portable information terminal, such as a laptop or notebook computer, or the like.
2. Description of Related Art
As the use of smaller, portable information terminals, such as laptop or notebook computers has increased over the years, work efficiency and productivity problems have arisen, particularly in trying to type or enter data using the existing keyboards that are built-into such devices. These problems include typing with an elevated error rate and/or typing at a slower speed in order to avoid high error rates, thus producing a decrease in productivity.
Although a number of persons have different views of why users have such problems with laptop or notebook computer keyboards, through extensive analysis applicants have determined the following: i) the degree of the problem cannot be substantially accounted for by a slightly smaller pitch (distance) between adjacent keycaps within a horizontal row or between adjacent horizontal rows in standard (non-“sub-notebook”) laptop or notebook computer keyboards; ii) the degree of the problem cannot be substantially accounted for by slightly smaller surface areas on the tops of keycaps on standard (non-“sub-notebook”) laptop or notebook computer keyboards; and iii) the degree of the problem cannot be substantially accounted for by a shorter travel distance of keys on standard (non-“sub-notebook”) laptop or notebook computer keyboards. What applicants have found is that the degree of the problem on standard (non-“sub-notebook”) laptop or notebook computer keyboards can only be substantially accounted for by the short height of the keys or keycaps on laptop or notebook computer keyboards.
Most manufacturers build standard size desktop keyboards having standard size keys and keycaps with standard heights, spacing (pitch), surface area, tapered (flared) shape and travel (see www.pcguide.com for definitions and explanations) in order to meet the heights, spacing, surface area, shape and travel to which users in a particular country or geographic region have been long accustomed and/or to meet ergonomic regulations. On all of these standard desktop keyboards, when a keycap is hit by a user the keycap will travel only part way down an adjacent keycap. Since the standard keycap is substantially pyramid-shaped, with the narrowest part at the top and the widest part at the bottom, it is very unlikely that a user will hit and fully press down an adjacent key even if his/her finger is off center on the target key. However, because of the lack of space available on laptop or notebook computers, manufacturers do not adhere to the accepted or familiar desktop keyboard standards when making laptop or notebook computer keyboards. Although the pitch, travel and keycap surface area on “sub-notebook” (miniature) laptop or notebook computers may substantially vary from the pitch, travel and keycap surface area on standard desktop computer keyboards and thereby adversely affect typing accuracy and speed, for the much more widely used standard size laptop or notebook computer, these pitch, travel and keycap surface area measurements are not greatly different in percentage terms from those on a standard desktop keyboard. On a standard size laptop or notebook computer keyboard the physical parameter exhibiting by far the biggest difference in percentage terms from a standard desktop keyboard is the height of the keycaps, with the keycaps on the laptop or notebook computer keyboard being substantially shorter. Because of these shorter keycaps on laptop or notebook computers, when a user pushes a keycap the user's finger moves downwardly and in fact travels past the bottom or widest point (flare at bottom of tapered keycap) of an adjacent keycap, and, therefore, the chances of hitting and pressing down the adjacent keycap are dramatically increased if the user's finger is not perfectly centered on the keycap it is hitting, thereby causing problems. Therefore, the applicants have determined that the crux of the problem seems to be in how far a user's finger travels (goes down) when operating a key on a laptop or notebook keyboard “in relation to” the adjacent key. That is, the main problem actually appears to be the relative movement of the user's finger. While a secondary problem with laptop or notebook keyboards is the lack of a separate numeric keypad.
Some users of laptop or notebook computers plug a normal or standard desktop keyboard into the available port in the laptop or notebook computer when not traveling or when at a fixed location for an extended period of time. However, this does not work when a user is mobile, for example, during travel, and it is neither convenient nor feasible to carry a full size external keyboard while traveling.
Although there are a number of patents that disclose keyboards with removable covers, no known patents disclose a portable keyboard for use with known portable information terminals to overcome the above-set forth problems, particularly when traveling. Examples of such known keyboards are shown in U.S. Pat. No. 5,975,780 to Fukami, U.S. Pat. No. 6,489,949 to Yin, U.S. Pat. No. 6,515,852 to Huang et al. and U.S. Pat. No. 6,558,057 to Lin. However, the keyboard devices and covers disclosed in the known patents do not show portable keyboards with reduced size enclosures and standard desktop keyboard size keys and fail to disclose the use of portable keyboards with a portable information terminal.
The present invention overcomes many of the known problems with existing keyboards for portable information terminals by providing a separate portable keyboard with mostly standard desktop keyboard size keys having a reduced-size enclosure for the keys with a removable cover that is readily connected to a portable information terminal, and which is less prone to error in inputting data.